STEPS: Modeling for Problem Solving in ES

Clearly define your goal (a question you want to answer, hypothesis you want to test, prediction you want to make) - as precisely as possible

• Design or Select your model

• Implement the model

• Evaluate the model and quantify uncertainty

• Apply the model to the goal

• Communicate model results

Designing/Selecting Models

• What are your inputs-outputs?

• What’s in the box (the model itself) that gives you a relationship between outputs and inputs?

Basic components of models

Inputs: Varying; think x of a x vs y regression

Parameters: single values that influence relationships in the model

Transfer Function (model): Equations that transfer inputs to outputs given parameters

Outputs: what you want to estimate

What’s in the box

• What are the processes/relationships that you think are important to translate inputs to output

• Transfer function (mathematical representation)

• Parameters, values that influences how the model relationships work

• There are often multiple “boxes” internal to a model

Simple model

Input: Change in unemployment rate

Output: Change in GDP

Parameters: Slope and intercept of the line The US “changes in unemployment – GDP growth” regression with the 95% confidence bands.

Transfer function: regression equations

What’s in the box

Often more complicated than a simple regression…

So we need to think through what the relationships are; the processes are that we want to take in to account

Conceptual models are a good place to start

Complex model

How will coral reefs change in the next decade given increased CO2

Input: Solar energy and atmospheric CO2, land DIC,

Output: Reef Dissolution, DOC/DIC export

Parameters: Many parameters that would be part of equations that estimate photosynthesis, calcification etc

Modeling changes both the changes in seawater chemistry in coral reef waters, as well as the responses of reef organisms.

Source UCAR

Conceptual models of the hydrologic cycle

Precipitation = Evapotranspiration + Change in Storage

P = ET + ΔS

(at global scales ΔS includes streamflow since that water is still “stored” in the earth

Model Complex Hydrology model

Goal - estimate streamflow fromm multiple source (surface and subsurface)

SERI-Fire

• More complex model couple sub-models

• How do ecological and human factors interact to influence fire regimes

Conceptual model as a flow chart (with example values)

[source](https://www.boundless.com/biology/textbooks/boundless-biology-textbook/ecosystems-46/energy-flow-through-ecosystems-257/productivity-within-trophic-levels-952-12212/](https://www.boundless.com/biology/textbooks/boundless-biology-textbook/ecosystems-46/energy-flow-through-ecosystems-257/productivity-within-trophic-levels-952-12212/)

Conceptual models can be of a processes (decision, assessment)

Serrano-Cinca C, Gutiérrez-Nieto B, Reyes NM, A Social and Environmental Approach to Microfinance Credit Scoring, Journal of Cleaner Production (2015), doi: 10.101

[Available from] (https://www.researchgate.net/publication/282855291_A_Social_and_Environmental_Approach_to_Microfinance_Credit_Scoring).

Figure 1. Flowchart of the social and environmental microcredit scoring decisional process. The model includes financial assessment and social impact assessment.

Conceptual models can be of a decision making processes

source

Model can also be about classification

Fig. 2. Flow-chart illustrating the working steps of glacial lake detection based on the normalized difference water index (NDWI), lake-outburst probability assessment and lake classi fi cation in the Indian Himalayas.

Rouce et al., Hydrol. Earth Syst. Sci., 20, 3455–3475, 2016 www.hydrol-earth-syst-sci.net/20/3455/2016/ doi:10.5194/hess-20-3455-2016

Types of Model

There are many different ways to classify models

A useful classification looks at how models deal with space, time, and process

Useful because the type of model will have implications for how you build and use/run the model

Stochastic - Deterministic

Stochastic: Model output is the probability of flood events of a magnitude greater than 500 m3/sec given rainfall probability distribution (artificial or generated from data) for a 100km2 watershed Deterministic: Model output is the depth of flood given a rainfall event of 10cm over a 100km2 watershed

source

Lumped …Spatially distributed

Lumped - single point in space, or space doesn’t matter

Spatially distributed - model is applied to different “patches” in space spatial units are independent

spatial units interact with each other

source

Static- Dynamic Time Varying

Static - Processes or Variables modeled do not evolve with time

Dynamic - model elements evolve through time - and variables/results at one time step typically depends on previous time step

source

Abstract - Physically/Process based

Abstract - relationship between inputs and output depends on parameters that don’t necessarily have a physical meaning

Physically based - parameters do have a physical meaning (could be measured) - relationships derived from first principles (theory) of how things work

Abstract - Physically/Process based

serc.carlton.edu Abstract

Physically based

Abstract Physically based http://ks.water.usgs.gov/pubs/reports/paclim99.html

Conceptual models: Composing

Pictorial representation of how you think about your system, whats included - will tell you really quickly if your model is appropriate for answering specific Qs

Return to conceptual model; expand to show how you will implement;Some model designers uses standard symbols for the different

Building Models

• PhD of Norman Crawford under supervision of Ray K Linsley at Stanford University in 1962

Conceptual Models

Assignment 1

Assignment 1:

For assignment one we will be creating two conceptual models: one of a model that we will build upon over the next 4 assignments, and the other to present in class. You will work in groups of 3-4.

Conceptual model to be presented in class:

Identify an environmental problem that would benefit from information that could be provided by model. Summarize the goal of the model in a single paragraph. Draw a conceptual model model, which again includes all that apply: inputs, outputs, important processes/mechanisms/interactions, reservoirs/stores, other intermediate variables or steps, relationships between variables. Put your conceptual model on a single slide and be prepared to present the key inputs and outputs of the model, and the purpose of the model in class

Conceptual model that will be built upon:

This will be a conceptual model of almond yield anomaly. Review the Lobell et al. 2006 paper; specifically look at the equation for almonds in table 2. Draw a conceptual model to represent this equation. Be sure to include all that apply: inputs, outputs. Identify the output (as precisely as you can) on the conceptual model. Be sure to understand what anomaly means! We will go over this together in class. Submit this model as a figure.

Submit the following to gauchospace

1. the one paragraph description of your model

2. the slide with your conceptual model for your selected model

3. slide/figure of the almond conceptual model

Submit as a group